Sukhumvit district is one of Bangkok's busiest sections of the city filled with office buildings, cheap and luxury hotels and practically any business under the sun catering to foreign expats and tourists on a holiday in Thailand. Sukhumvit's claim to fame are also Nana and Soi Cowboy, which are two of the city's popular red light districts.
As a popular tourist destination in Bangkok, Sukhumvit is what most tourists do not on a budget prefer to stay. It's true that Sukhumvit has the most moderately and luxurious priced hotels. But with so many hotels competing for tourists dollars it's not at all difficult to find quality budget hotels on Sukhumvit Road for around Baht 1000 to Baht 1500 a night. There are hotels with room rates around B500 but the quality of such cheap hotels are not so desirable. If you know you have a certain level of comfort that has to be meet, such as air conditioning, it's best not to choose a hotel in Sukhumvit under Baht 800.
Sukhumvit Road is a long avenue that stretches all the way from central Bangkok and down south to Pattaya, a popular beach side city. But the best areas to find affordable hotels on Sukhumvit Road is between Soi 1 through Soi 55 (A Soi in Thai means a side street or lane).
Soi 1 is where Sukhumvit Road begins and it's also where Nana red light district starts. There are many budget hotels throughout that area as well as 4 star accommodations. Down on Soi 4 Boss Hotel and Heaven @ 4 Hotel, two newly built properties in that area are good examples of budget hotels in the Sukhumvit district. Because both budget hotels are located in Nana red light district it might not be an ideal family friendly hotel. Boss Hotel and Heaven @ 4 charge around Baht 1500 per night. I've noticed that newer hotels usually offer promotions for free nights after a minimum period of stay so it's a good idea to seek out newly opened hotels in Bangkok.
Further down on Sukhumvit Road near the Asoke Junction and adjacent to the Soi Cowboy red light district, tourists can also find cheaper accommodations in Bangkok for around Baht 1300 per night. Two good examples are Asoke Suites and Merisess Sukhumvit 16. Both are not the newest or shiniest but not more than 4 years old so the conditions of both hotels are still a good choice for staying in an active and lively section of Bangkok.
A major advantage for staying near these hotels is that there are Sky Trains running on elevated train tracks right about Sukhumvit Road. The Sky Train is a popular and efficient method of transportation for getting around the commercial shopping zones in Bangkok.